CN114063694A - Voltage modulation method and device, computer equipment and storage medium - Google Patents

Voltage modulation method and device, computer equipment and storage medium Download PDF

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Publication number
CN114063694A
CN114063694A CN202111252369.8A CN202111252369A CN114063694A CN 114063694 A CN114063694 A CN 114063694A CN 202111252369 A CN202111252369 A CN 202111252369A CN 114063694 A CN114063694 A CN 114063694A
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modules
voltage
determining
triangular carrier
time
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CN114063694B (en
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彭莱
薛云涛
鄞庆佳
朱劲磊
朱博
欧嘉俊
邓烨恒
徐敏
吴彦伟
易家昌
张青立
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Guangzhou Power Supply Bureau of Guangdong Power Grid Co Ltd
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Guangzhou Power Supply Bureau of Guangdong Power Grid Co Ltd
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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
    • G05F1/10—Regulating voltage or current
    • G05F1/46—Regulating voltage or current wherein the variable actually regulated by the final control device is dc
    • G05F1/56—Regulating voltage or current wherein the variable actually regulated by the final control device is dc using semiconductor devices in series with the load as final control devices
    • G05F1/561—Voltage to current converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/145—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means
    • H02M7/155—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means using semiconductor devices only
    • H02M7/162—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means using semiconductor devices only in a bridge configuration
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Automation & Control Theory (AREA)
  • Inverter Devices (AREA)

Abstract

The application relates to a voltage modulation method, a voltage modulation device, computer equipment and a storage medium. The method comprises the following steps: respectively determining an integer part and a decimal part of a quotient of a target modulation voltage and a rated voltage as an initial value of a module number and an adjustment reference value; calculating dynamic switching time according to the period of the triangular carrier wave and the adjustment reference value; determining timing time according to the triangular carrier and a preset timing rule; comparing the timing time with the dynamic switching time; if the timing time is greater than or equal to the dynamic switching time and less than the amplitude of the triangular carrier wave, determining that the number of the input modules is equal to the initial value of the number of the modules; if the timing time is less than the dynamic switching time, determining that the number of the switching modules is equal to the number of the adjusting modules, wherein the number of the adjusting modules is the initial value of the number of the modules plus 1; voltage sequencing is carried out according to the number of the input modules, and a driving signal is output; and the driving signals are used for switching in or switching out each submodule in the bridge arm. By adopting the method, the voltage modulation precision of the modular multi-level converter in the flexible direct current power transmission system can be improved.

Description

Voltage modulation method and device, computer equipment and storage medium
Technical Field
The present application relates to the field of flexible dc power transmission technologies, and in particular, to a voltage modulation method and apparatus, a computer device, and a storage medium.
Background
Converter valves in a flexible direct-current transmission system are generally high in voltage level, a modular multilevel converter is adopted in a main circuit topology, the number of bridge arm series submodules is usually hundreds, the conventional carrier phase shift modulation (SPWM) and voltage space vector modulation (SVPWM) are increased along with the number of modules, the calculated amount is increased sharply, the converter is difficult to apply at the level of more than 5, the problem of overlarge calculated amount also exists in the voltage sharing of the modules in the bridge arms, and the voltage sharing effect is influenced by harmonic waves and is difficult to control.
The modular multilevel converter in the flexible direct current transmission system generally adopts a nearest level approach method for modulation. However, in the recent level approximation method, an error inevitably exists between the modulation voltage and the step wave output by the converter valve, wherein on the premise that the number of the bridge arm sub-modules is certain, the calculation period of the controller is also one of error sources, and the controller calculates the number of the bridge arm input modules once in each control period and updates the output driving signal, so that the control period determines the minimum width of the step wave output by the converter valve. The smaller the control period is, the higher the approximation degree is, but in practical engineering, the control period is usually in the order of hundred microseconds, and in recent level approximation modulation methods, the number of input modules is usually rounded directly, which all cause certain modulation errors.
Disclosure of Invention
In view of the above, it is desirable to provide a voltage modulation method, a voltage modulation apparatus, a computer device, and a storage medium that can improve modulation accuracy.
A voltage modulation method is applied to a modular multilevel converter, and comprises the following steps:
respectively determining an integer part and a decimal part of a quotient of a target modulation voltage and a rated voltage as an initial value of a module number and an adjustment reference value;
calculating dynamic switching time according to the period of the triangular carrier wave and the adjustment reference value;
determining timing time according to the triangular carrier and a preset timing rule;
comparing the timing time with the dynamic switching time;
if the timing time is greater than or equal to the dynamic switching time and less than the amplitude of the triangular carrier, determining that the number of input modules is equal to the initial value of the number of modules;
if the timing time is less than the dynamic switching time, determining that the number of input modules is equal to the number of adjustment modules, wherein the number of adjustment modules is the initial value of the number of modules plus 1;
voltage sequencing is carried out according to the number of the input modules, and a driving signal is output; the driving signals are used for switching in or switching out each submodule in the bridge arm.
In one embodiment, the method further comprises the following steps:
determining the charging and discharging directions of the bridge arm current;
when the bridge arm current is in the charging direction, the driving signals are used for driving a plurality of submodules with the lowest voltage to be put into operation, and the rest submodules are all in a cutting-off state;
wherein the number of the sub-modules put in is equal to the number of the put-in modules.
In one embodiment, the method further comprises the following steps:
when the bridge arm current is in the discharging direction, the driving signals are used for driving a plurality of submodules with the highest voltage to be put into operation, and the rest submodules are all in a cutting-off state.
In one embodiment, the dynamic switching time is equal to a product of one-half of the period and the adjustment reference value.
In one embodiment, the preset rule includes:
the timing time corresponding to the trough position of the triangular carrier is zero, and the timing time is increased progressively according to a preset step length at the rising edge stage of the triangular carrier;
and entering the falling edge of the triangular carrier wave until the peak position of the triangular carrier wave is increased, and decreasing the timing time to zero according to the step length.
In one embodiment, when the target modulation voltage is an upper bridge arm modulation voltage, the number of the input modules is the number of input sub-modules of an upper bridge arm.
In one embodiment, when the target modulation voltage is a lower bridge arm modulation voltage, the number of the input modules is the number of input sub-modules of the lower bridge arm.
A voltage modulation device applied to a Modular Multilevel Converter (MMC), the device comprising:
the first determining module is used for respectively determining an integer part and a decimal part of a quotient of the target modulation voltage and the rated voltage as a module number initial value and an adjustment reference value;
the dynamic switching time determining module is used for calculating dynamic switching time according to the period of the triangular carrier and the adjustment reference value;
the time determining module is used for determining timing time according to the triangular carrier and a preset timing rule;
the comparison module is used for comparing the timing time with the dynamic switching time;
the second determining module is used for determining that the number of the input modules is equal to the initial value of the number of the modules when the timing time is greater than or equal to the dynamic switching time and is less than the amplitude;
the third determining module is used for determining that the number of input modules is equal to the number of adjusting modules when the timing time is less than the dynamic switching time, wherein the number of adjusting modules is the sum of 1 and the initial value of the number of modules;
the driving signal output module is used for sequencing voltages according to the number of the input modules and outputting driving signals; the driving signals are used for switching in or switching out each submodule in the bridge arm.
A computer device comprising a memory and a processor, the memory storing a computer program, the processor implementing the following steps when executing the computer program:
respectively determining an integer part and a decimal part of a quotient of a target modulation voltage and a rated voltage as an initial value of a module number and an adjustment reference value;
calculating dynamic switching time according to the period of the triangular carrier wave and the adjustment reference value;
determining timing time according to the triangular carrier and a preset timing rule;
comparing the timing time with the dynamic switching time;
if the timing time is greater than or equal to the dynamic switching time and less than the amplitude of the triangular carrier, determining that the number of input modules is equal to the initial value of the number of modules;
if the timing time is less than the dynamic switching time, determining that the number of input modules is equal to the number of adjustment modules, wherein the number of adjustment modules is the initial value of the number of modules plus 1;
voltage sequencing is carried out according to the number of the input modules, and a driving signal is output; the driving signals are used for switching in or switching out each submodule in the bridge arm.
A computer-readable storage medium, on which a computer program is stored which, when executed by a processor, carries out the steps of:
respectively determining an integer part and a decimal part of a quotient of a target modulation voltage and a rated voltage as an initial value of a module number and an adjustment reference value;
calculating dynamic switching time according to the period of the triangular carrier wave and the adjustment reference value;
determining timing time according to the triangular carrier and a preset timing rule;
comparing the timing time with the dynamic switching time;
if the timing time is greater than or equal to the dynamic switching time and less than the amplitude, determining that the number of the input modules is equal to the initial value of the number of the modules;
if the timing time is less than the dynamic switching time, determining that the number of input modules is equal to the number of adjustment modules, wherein the number of adjustment modules is the initial value of the number of modules plus 1;
voltage sequencing is carried out according to the number of the input modules, and a driving signal is output; the driving signals are used for switching in or switching out each submodule in the bridge arm.
According to the voltage modulation method, the voltage modulation device, the computer equipment and the storage medium, the integer part and the decimal part of the quotient of the target modulation voltage and the rated voltage are respectively determined as the initial value of the number of modules and the adjustment reference value, the dynamic switching time is calculated by utilizing the adjustment reference value and the period of the triangular carrier, the timing time is determined according to the triangular carrier, the number of the modules which are switched in is dynamically controlled to be repeatedly switched between the initial value of the number of modules and the number of the adjustment modules according to the size relation between the timing time and the dynamic switching time, and the voltage modulation precision is improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic flow chart of a voltage modulation method according to an embodiment;
FIG. 2 is a schematic flow chart of a voltage modulation method according to another embodiment;
FIG. 3 is a diagram illustrating the relationship between the number of modules inserted and the timing time in one embodiment;
FIG. 4 is a block diagram of a voltage modulation device according to an embodiment;
FIG. 5 is a block diagram showing the structure of a voltage modulation device according to another embodiment;
FIG. 6 is a diagram illustrating an internal structure of a computer device according to an embodiment.
Detailed Description
To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Embodiments of the present application are set forth in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
It will be understood that the terms "first," "second," and the like as used herein may be used herein to describe various features, but these features are not limited by these terms. These terms are only used to distinguish one feature from another.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" or "comprising," or the like, specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.
The voltage modulation method is applied to a modular multi-level converter in a flexible direct current transmission system. Each phase of the modular multilevel converter is composed of an upper bridge arm and a lower bridge arm, each bridge arm is formed by connecting a plurality of sub-modules in series, and each bridge arm is connected with a reactor in series. The modular multilevel converter is different from a two-level or three-level voltage source converter bridge arm in that the bridge arm of the modular multilevel converter performs switching actions in various combination modes, so that the output voltage of the modular multilevel converter is controllable. The switching mode of each semiconductor switching device in the bridge arm can be determined according to the target modulation voltage of the bridge arm, and the switching modes can determine the charging and discharging time of the capacitor, so that the balance of the capacitor voltage is realized.
As shown in fig. 1, an embodiment of the present application provides a voltage modulation method, including the following steps:
step 101, respectively determining an integer part and a decimal part of a quotient of a target modulation voltage and a rated voltage as an initial value of a module number and an adjustment reference value.
The target modulation voltage is a target voltage required to be output by the bridge arm, and the rated voltage is the rated voltage of the normal work of the bridge arm. And calculating the quotient of the target modulation voltage and the rated voltage (namely the target modulation voltage/the rated voltage), determining the integral part of the calculation result as the initial value of the number of the modules, and determining the decimal part as the adjustment reference value.
And 102, calculating dynamic switching time according to the period of the triangular carrier and the adjustment reference value.
The dynamic switching time is the time for dynamically switching one module on the basis of the initial value of the number of the modules, and the modulation precision of the voltage mean value is improved by using the dynamically switched modules; the period of the triangular carrier is a given parameter. And modulating the adjustment reference value by utilizing the triangular carrier wave, and calculating the dynamic switching time.
And 103, determining timing time according to the triangular carrier and a preset timing rule.
And performing time conversion by utilizing a triangular carrier according to a preset timing rule, and determining the timing time corresponding to the current moment, wherein the timing time is used for comparing with the dynamic switching time.
And step 104, comparing the timing time with the dynamic switching time.
And 105, if the timing time is greater than or equal to the dynamic switching time and less than the amplitude of the triangular carrier, determining that the number of the input modules is equal to the initial value of the number of the modules.
Wherein the amplitude of the triangular carrier is a given parameter. And when the timing time is greater than or equal to the dynamic switching time, determining the initial value of the module number as the number of the modules to be switched in.
And 106, if the timing time is less than the dynamic switching time, determining that the number of the switching modules is equal to the number of the adjusting modules, wherein the number of the adjusting modules is the initial value of the number of the modules plus 1.
In the falling edge stage of the triangular carrier, more modules are required to be put in, and the voltage mean value is further increased, so when the timing time is less than the dynamic switching time, the number of the put-in modules is determined as the number of the adjusting modules, the number of the adjusting modules is the initial value of the number of the modules plus 1, namely if the initial value of the number of the modules is N, the number of the adjusting modules is N + 1.
Step 107, voltage sequencing is carried out according to the number of the input modules, and a driving signal is output; and the driving signals are used for switching in or switching out each submodule in the bridge arm.
The voltage sorting means that all modules are sorted according to the voltage, and then a plurality of sub-modules of the input module are selected in sequence in all sub-modules according to the number of the input modules to be input. The driving signal is used for driving each corresponding sub-module on the bridge arm to be switched in or switched off, namely, the sub-modules needing to be switched in are selected according to the voltage sequence, and the rest sub-modules are switched off.
According to the voltage modulation method, the integral part and the decimal part of the quotient of the target modulation voltage and the rated voltage are respectively determined as the initial value of the number of modules and the adjustment reference value, the dynamic switching time is calculated by utilizing the adjustment reference value and the period of the triangular carrier wave, the timing time is determined according to the triangular carrier wave, the number of the modules which are switched in is dynamically controlled to be repeatedly switched between the initial value of the number of modules and the number of the adjustment modules according to the size relation of the timing time and the dynamic switching time, and the voltage modulation precision is improved.
As shown in fig. 2, in one embodiment, the voltage modulation method further includes:
step 201, the integral part and the decimal part of the quotient of the target modulation voltage and the rated voltage are respectively determined as the initial value of the number of modules and the adjustment reference value.
Step 202, calculating dynamic switching time according to the period of the triangular carrier and an adjustment reference value;
step 203, determining timing time according to the triangular carrier and a preset timing rule;
step 204, comparing the timing time with the dynamic switching time;
step 205, if the timing time is greater than or equal to the dynamic switching time and less than the amplitude of the triangular carrier, determining that the number of input modules is equal to the initial value of the number of modules;
step 206, if the timing time is less than the dynamic switching time, determining that the number of the switching modules is equal to the number of the adjusting modules, wherein the number of the adjusting modules is the initial value of the number of the modules plus 1;
and step 207, determining the charging and discharging directions of the bridge arm current.
Step 208, voltage sequencing is carried out according to the number of the input modules and driving signals are output; and the driving signals are used for switching in or switching out each submodule in the bridge arm.
When the bridge arm current is in the charging direction, the driving signals are used for driving a plurality of submodules with the lowest voltage to be switched in, and the rest submodules are in a cut-off state; and the number of the input sub-modules is equal to the number of the input modules.
According to the difference of the charging and discharging directions of the bridge arm current, the voltage sequence of the submodules needing to be input is also different, and the charging and discharging directions of the bridge arm current can be measured and determined through a bridge arm current direction measuring device arranged in the modular multilevel converter. When the bridge arm current is in the charging direction, the submodules needing to be put in are selected according to the number of the put-in modules, namely the submodules with the lowest voltage in the voltage sequence, namely the submodules are selected according to the sequence of the voltage from low to high.
In one embodiment, when the bridge arm current is in the discharging direction, the driving signal is used for driving a plurality of submodules with the highest voltage to be switched in, and the rest submodules are all in a cutting-off state.
When the bridge arm current is in the discharging direction, the submodules needing to be put in are selected according to the number of the put-in modules, namely the submodules with the highest voltage in the voltage sequence, namely the submodules are selected according to the sequence of the voltage from high to low.
In one embodiment, the dynamic switching time is determined according to the following formula:
Tm＝0.5×Tr×n
wherein, TmDynamic switching time; t isrIs the period of the triangular carrier wave; n is an adjustment reference value.
Referring to FIG. 3, in one embodiment, the timing rule for determining the timing time is:
and in the rising edge stage of the triangular carrier, the timing time is increased progressively according to a preset step length until the timing time is increased progressively to the peak position of the triangular carrier, then the timing time enters the falling edge of the triangular carrier, the timing time is decreased progressively to zero according to the preset step length in the stage, and the process is repeated. The generation time of the triangular carrier depends on a carrier generator, the timing time corresponds to the time for modulating the voltage, the corresponding time of the modulation time is determined according to the timing of the triangular carrier, the number of the input modules at the time is further determined, and a corresponding driving signal is output.
In one embodiment, when the target modulation voltage is an upper bridge arm modulation voltage for modulating an upper bridge arm, the number of input modules is the number of input sub-modules of the upper bridge arm. Specifically, if the upper bridge arm needs to be voltage-modulated, the number of input modules is determined by the voltage method, a plurality of sub-modules corresponding to the input modules in the upper bridge arm are input, and the rest sub-modules of the upper bridge arm are all cut off.
In one embodiment, when the target modulation voltage is a lower bridge arm modulation voltage for modulating a lower bridge arm, the number of input modules is the number of input sub-modules of the lower bridge arm. Specifically, if the lower bridge arm needs to be voltage-modulated, the number of input modules is determined by the voltage method, a plurality of sub-modules corresponding to the input modules in the lower bridge arm are input, and the rest sub-modules of the lower bridge arm are all cut off.
It should be understood that although the various steps in the flow charts of fig. 1-2 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least some of the steps in fig. 1-2 may include multiple steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, which are not necessarily performed in sequence, but may be performed in turn or alternately with other steps or at least some of the other steps.
For example, if the target modulation voltage is 100kV and the rated voltage is 2.1kV, the calculation result is 100/2.1-47.62, i.e. the initial value N of the module number is 47, and the adjustment reference value is 0.62. The period of the triangular carrier wave is 0.002s, the amplitude is 0.001, the preset step length is 0.0005, the timing time t corresponding to the triangular carrier wave is 0 at the trough, the timing time t is increased progressively according to the preset step length along the rising edge of the triangular carrier wave until the t at the peak position is increased progressively to be equal to the amplitude of the triangular carrier wave, then the timing time t enters the falling edge of the triangular carrier wave, and the timing time t is decreased progressively from the amplitude of the triangular carrier wave to 0.001 according to the preset step length until the timing time t is decreased progressively to the trough position to be equal to 0. Acquiring the timing time t corresponding to the voltage modulation moment, and calculating the dynamic switching timeInter TmWhen the input module number M is 0.5 × 0.002 × 0.62 to 0.00062, the input module number M is:
Figure BDA0003322842950000111
switching control is carried out according to the number M of the input modules determined at each moment, when the current direction of a bridge arm is the charging direction, M sub-modules with the lowest driving voltage are output to drive, and the rest sub-modules are cut off; when the direction of the bridge arm is the discharging direction, the M sub-modules with the highest driving voltage are input by outputting driving signals, and the rest sub-modules are cut off, so that the purpose of improving the voltage modulation precision is achieved.
In one embodiment, as shown in fig. 4, there is provided a voltage modulation apparatus 400 comprising: a first determination module 401, a dynamic switching time determination module 402, a time determination module 403, a comparison module 404, a second determination module 405, a third determination module 406, and a driving signal output module 407, wherein:
a first determining module 401, configured to determine an integer part and a fractional part of a quotient between a target modulation voltage and a rated voltage as a module number initial value and an adjustment reference value, respectively;
the dynamic switching time determining module 402 is configured to calculate dynamic switching time according to a period of the triangular carrier and an adjustment reference value;
a time determining module 403, configured to determine a timing time according to the triangular carrier and a preset timing rule;
a comparison module 404, configured to compare the timing time and the dynamic switching time;
a second determining module 405, configured to determine that the number of modules to be switched in is equal to the initial value of the number of modules when the timing time is greater than or equal to the dynamic switching time and is less than the amplitude of the triangular carrier;
a third determining module 406, configured to determine, when the timing time is less than the dynamic switching time, that the number of the input modules is equal to the number of the adjustment modules, where the number of the adjustment modules is equal to the initial value of the number of the modules plus 1;
the driving signal output module 407 is used for sequencing voltages according to the number of input modules and outputting driving signals; and the driving signals are used for switching in or switching out each submodule in the bridge arm.
As shown in fig. 5, in one embodiment, the voltage modulation apparatus 400 further includes:
and a current direction determining module 408, configured to determine a charging and discharging direction of the bridge arm current.
For the specific definition of the voltage modulation device, reference may be made to the above definition of the voltage modulation method, which is not described herein again. The modules in the voltage regulating device can be wholly or partially realized by software, hardware and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.
In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as shown in fig. 6. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device comprises a nonvolatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The communication interface of the computer device is used for carrying out wired or wireless communication with an external terminal, and the wireless communication can be realized through WIFI, an operator network, NFC (near field communication) or other technologies. The computer program is executed by a processor to implement a voltage modulation method. The display screen of the computer equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, a key, a track ball or a touch pad arranged on the shell of the computer equipment, an external keyboard, a touch pad or a mouse and the like.
Those skilled in the art will appreciate that the architecture shown in fig. 6 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices to which the disclosed aspects apply, as particular computing devices may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.
In one embodiment, a computer device is provided, comprising a memory and a processor, the memory having a computer program stored therein, the processor implementing the following steps when executing the computer program:
respectively determining an integer part and a decimal part of a quotient of a target modulation voltage and a rated voltage as an initial value of a module number and an adjustment reference value;
calculating dynamic switching time according to the period of the triangular carrier wave and the adjustment reference value;
determining timing time according to the triangular carrier and a preset timing rule;
comparing the timing time with the dynamic switching time;
if the timing time is greater than or equal to the dynamic switching time and less than the amplitude of the triangular carrier, determining that the number of input modules is equal to the initial value of the number of modules;
if the timing time is less than the dynamic switching time, determining that the number of input modules is equal to the number of adjustment modules, wherein the number of adjustment modules is the initial value of the number of modules plus 1;
voltage sequencing is carried out according to the number of the input modules, and a driving signal is output; the driving signals are used for switching in or switching out each submodule in the bridge arm.
In one embodiment, the processor, when executing the computer program, further performs the steps of:
and determining the charging and discharging directions of the bridge arm current.
In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, which when executed by a processor performs the steps of:
respectively determining an integer part and a decimal part of a quotient of a target modulation voltage and a rated voltage as an initial value of a module number and an adjustment reference value;
calculating dynamic switching time according to the period of the triangular carrier wave and the adjustment reference value;
determining timing time according to the triangular carrier and a preset timing rule;
comparing the timing time with the dynamic switching time;
if the timing time is greater than or equal to the dynamic switching time and less than the amplitude of the triangular carrier, determining that the number of input modules is equal to the initial value of the number of modules;
if the timing time is less than the dynamic switching time, determining that the number of input modules is equal to the number of adjustment modules, wherein the number of adjustment modules is the initial value of the number of modules plus 1;
voltage sequencing is carried out according to the number of the input modules, and a driving signal is output; the driving signals are used for switching in or switching out each submodule in the bridge arm.
In one embodiment, the computer program when executed by the processor further performs the steps of:
and determining the charging and discharging directions of the bridge arm current.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database or other medium used in the embodiments provided herein can include at least one of non-volatile and volatile memory. Non-volatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical storage, or the like. Volatile Memory can include Random Access Memory (RAM) or external cache Memory. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM), among others.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A voltage modulation method is applied to a modular multilevel converter and is characterized by comprising the following steps:
respectively determining an integer part and a decimal part of a quotient of a target modulation voltage and a rated voltage as an initial value of a module number and an adjustment reference value;
calculating dynamic switching time according to the period of the triangular carrier wave and the adjustment reference value;
determining timing time according to the triangular carrier and a preset timing rule;
comparing the timing time with the dynamic switching time;
if the timing time is greater than or equal to the dynamic switching time and less than the amplitude of the triangular carrier, determining that the number of input modules is equal to the initial value of the number of modules;
if the timing time is less than the dynamic switching time, determining that the number of input modules is equal to the number of adjustment modules, wherein the number of adjustment modules is the initial value of the number of modules plus 1;
voltage sequencing is carried out according to the number of the input modules, and a driving signal is output; the driving signals are used for switching in or switching out each submodule in the bridge arm.
2. The voltage modulation method of claim 1, further comprising:
determining the charging and discharging directions of the bridge arm current;
when the bridge arm current is in the charging direction, the driving signals are used for driving a plurality of submodules with the lowest voltage to be put into operation, and the rest submodules are all in a cutting-off state;
wherein the number of the inputted sub-modules is equal to the number of the inputted modules.
3. The voltage modulation method of claim 2, further comprising:
when the bridge arm current is in the discharging direction, the driving signals are used for driving a plurality of submodules with the highest voltage to be put into operation, and the rest submodules are all in a cutting-off state.
4. The voltage modulation method according to claim 1, wherein the dynamic switching time is equal to a product of one-half of the period and the adjustment reference value.
5. The voltage modulation method according to claim 1, wherein the preset rule comprises:
the timing time corresponding to the trough position of the triangular carrier is zero, and the timing time is increased progressively according to a preset step length at the rising edge stage of the triangular carrier;
and entering the falling edge of the triangular carrier wave until the peak position of the triangular carrier wave is increased, and decreasing the timing time to zero according to the step length.
6. The voltage modulation method according to any one of claims 1 to 5, wherein when the target modulation voltage is an upper arm modulation voltage, the number of input modules is the number of input sub-modules of an upper arm.
7. The voltage modulation method according to any one of claims 1 to 5, wherein when the target modulation voltage is a lower arm modulation voltage, the number of input modules is the number of input submodules of a lower arm.
8. A voltage modulation device applied to a modular multilevel converter is characterized by comprising:
the first determining module is used for respectively determining an integer part and a decimal part of a quotient of the target modulation voltage and the rated voltage as a module number initial value and an adjustment reference value;
the dynamic switching time determining module is used for calculating dynamic switching time according to the period of the triangular carrier and the adjustment reference value;
the time determining module is used for determining timing time according to the triangular carrier and a preset timing rule;
the comparison module is used for comparing the timing time with the dynamic switching time;
the second determining module is used for determining that the number of the input modules is equal to the initial value of the number of the modules when the timing time is greater than or equal to the dynamic switching time and is less than the amplitude of the triangular carrier;
the third determining module is used for determining that the number of input modules is equal to the number of adjusting modules when the timing time is less than the dynamic switching time, wherein the number of adjusting modules is the sum of 1 and the initial value of the number of modules;
the driving signal output module is used for sequencing voltages according to the number of the input modules and outputting driving signals; the driving signals are used for switching in or switching out each submodule in the bridge arm.
9. A computer device comprising a memory and a processor, the memory storing a computer program, wherein the processor implements the steps of the method of any one of claims 1 to 7 when executing the computer program.
10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 7.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024040395A1 (en) * 2022-08-22 2024-02-29 宁德时代未来能源(上海)研究院有限公司 Switching control method and apparatus, energy storage system, device, medium, and product

Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101836352A (en) * 2007-10-24 2010-09-15 大金工业株式会社 Power conversion device
CN101951162A (en) * 2010-09-06 2011-01-19 东北电力大学 Pulse width control method of modular multilevel converter
CN102780224A (en) * 2012-08-08 2012-11-14 西安交通大学 Seamless cut-off controlling method for chained multi-level inverter error unit
WO2014166261A1 (en) * 2013-04-10 2014-10-16 国家电网公司 Modulation method for grouping stair waves of modularization multilevel converter submodules
WO2015074529A1 (en) * 2013-11-19 2015-05-28 国家电网公司 Sub-module capacitor voltage balancing optimization method for modular multilevel converter
CN105337522A (en) * 2015-11-03 2016-02-17 湖南大学 Double-carrier-wave modulation method of modular multilevel converter
CN105553310A (en) * 2015-12-31 2016-05-04 湖南大学 Low-modulation-index control method for modular multi-level current converter
CN106533235A (en) * 2016-12-26 2017-03-22 中国西电电气股份有限公司 Half-bridge MMC converter including redundancy control and control method thereof
CN107579677A (en) * 2017-10-16 2018-01-12 云南电网有限责任公司电力科学研究院 A kind of switching frequency computational methods of MMC submodules
US20190068080A1 (en) * 2017-08-28 2019-02-28 Tsinghua University Method and device for voltage balancing of dc bus capacitors of neutral-point clamped four-level inverter
CN110572066A (en) * 2019-09-30 2019-12-13 华中科技大学 optimal modulation method of full-bridge modular multilevel converter
CN111342691A (en) * 2020-04-09 2020-06-26 华中科技大学 Si device and SiC device mixed MMC and modulation method thereof
CN112152477A (en) * 2020-10-21 2020-12-29 华中科技大学 Improved flying capacitor MMC topology and modulation strategy thereof
CN112865573A (en) * 2021-03-16 2021-05-28 上海电力大学 MMC carrier modulation method based on double modulation waves
CN112910292A (en) * 2021-01-19 2021-06-04 华中科技大学 MMC modulation method provided with half-voltage SiC sub-module and MMC

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101836352A (en) * 2007-10-24 2010-09-15 大金工业株式会社 Power conversion device
CN101951162A (en) * 2010-09-06 2011-01-19 东北电力大学 Pulse width control method of modular multilevel converter
CN102780224A (en) * 2012-08-08 2012-11-14 西安交通大学 Seamless cut-off controlling method for chained multi-level inverter error unit
WO2014166261A1 (en) * 2013-04-10 2014-10-16 国家电网公司 Modulation method for grouping stair waves of modularization multilevel converter submodules
WO2015074529A1 (en) * 2013-11-19 2015-05-28 国家电网公司 Sub-module capacitor voltage balancing optimization method for modular multilevel converter
CN105337522A (en) * 2015-11-03 2016-02-17 湖南大学 Double-carrier-wave modulation method of modular multilevel converter
CN105553310A (en) * 2015-12-31 2016-05-04 湖南大学 Low-modulation-index control method for modular multi-level current converter
CN106533235A (en) * 2016-12-26 2017-03-22 中国西电电气股份有限公司 Half-bridge MMC converter including redundancy control and control method thereof
US20190068080A1 (en) * 2017-08-28 2019-02-28 Tsinghua University Method and device for voltage balancing of dc bus capacitors of neutral-point clamped four-level inverter
CN107579677A (en) * 2017-10-16 2018-01-12 云南电网有限责任公司电力科学研究院 A kind of switching frequency computational methods of MMC submodules
CN110572066A (en) * 2019-09-30 2019-12-13 华中科技大学 optimal modulation method of full-bridge modular multilevel converter
CN111342691A (en) * 2020-04-09 2020-06-26 华中科技大学 Si device and SiC device mixed MMC and modulation method thereof
CN112152477A (en) * 2020-10-21 2020-12-29 华中科技大学 Improved flying capacitor MMC topology and modulation strategy thereof
CN112910292A (en) * 2021-01-19 2021-06-04 华中科技大学 MMC modulation method provided with half-voltage SiC sub-module and MMC
CN112865573A (en) * 2021-03-16 2021-05-28 上海电力大学 MMC carrier modulation method based on double modulation waves

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024040395A1 (en) * 2022-08-22 2024-02-29 宁德时代未来能源(上海)研究院有限公司 Switching control method and apparatus, energy storage system, device, medium, and product

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